• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.9
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• pp.47-53
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• 2011

The signal transmission properties of the connector such as insertion loss and return loss are investigated using analysis procedure of S-parameter simulation, equivalent model extraction, and characteristic impedance calculation. S-parameter simulation is performed by connector's modeling and solving based on 3-dimensional finite element method. The connector's equivalent model of ${\pi}$ type is are proposed and extracted with an optimization process of circuit analysis simulator. The characteristic impedance of the connector is calculated with results of circuit analysis simulation and S-parameter data. According to the connector's characteristic impedance, it's revised design is carried out. In this work, the connector's effective contact area is increased and its body is applied as a high dielectric material in order to increase its capacitance and then obtain impedance matching. Therefore, return loss of the connector is improved by approximately 10 dB due to its design revision.

• Structural Engineering and Mechanics
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• v.22 no.4
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• pp.433-447
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• 2006

The problem of very large deflection of a circular cantilever arc device subjected to inward or outward polar force is studied. An exact elliptic integral solution is derived for the two cases and the results are checked using large displacement finite element analysis via the ANSYS package by performing a new novel modeling simulation technique for this problem. Excellent agreements have been obtained between the exact analytical solution and the numerical approach. From this study, a design chart for engineers is developed to predict the required value for the inward polar force for the device to switch on for a given angle forming the circular arc (${\theta}_o$). This study has several interesting applications in mechanical engineering, integrated circuit technology, nanotechnology and especially in microelectromechanical systems (MEMs) such as a MEM circular device switch subjected to attractive or repulsive magnetic forces due to the attachments of two magnetic poles at the fixed and at the free end of the circular cantilever arc switch device.

• ETRI Journal
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• v.29 no.5
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• pp.614-618
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• 2007

A miniaturized bandstop filter (BSF) is introduced in this paper. The filter consists of one meander spurline and a pair of capacitively loaded stubs. The meander spurline with low resonant frequency and improved slow-wave factor exhibits excellent resonant bandgap characteristics which can be modeled by a longitudinally coupled resonator. The design of the proposed microstrip BSF is presented, and its performance is measured. Measurements show that there is a stopband from 2.3 to 5.6 GHz with $S_{21}$ less than -20 dB. The total length of this BSF equals 23 mm.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.1940-1942
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• 2001

Magnetic Levitation System(MLS) levitates a steel ball to the desired position in the gravity field using electromagnetic force. MLS consists of light sensor to measure the position of steel ball and an electromagnet to control the position of the ball, that composes a feedback control system. This work does not use a steel ball with constant mass but variable mass steel balls as magnetic levitation targets. Differential equation of electric circuit for electromagnet and motion equation of the movement of steel ball are derived for modeling nonlinear system, that will be linearized at the nominal operating point. We propose a digital control that can levitate a steel ball of which weight is not known for ED-4810 system. Algorithm for estimating ball weight and feedback control are implemented in digital scheme under pentium PC equiped with A/D and D/A converter, ACL-8112, using C-language. Simulation and experimental results are given to show the usefulness of the proposed controller.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.349-350
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• 2016

In the magnetically coupled wireless power transmit (WPT), the study of the multi-dimensional transmission coil to solve the low power transmission efficiency from the location of transmit coil and receiving coil is being developed. This paper, an important step in this study, presents the magnetically coupled model of the WPT system consist of the two-dimensional transmit coil and verifies by the simulation and experiment. The induced model in this paper can be used to design the WPT circuit and controller for the maximum transmission efficiency.

• Journal of the Korea Society for Simulation
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• v.7 no.1
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• pp.15-26
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• 1998

In building a shell-based FMS, which is known as one of the top-down approaches in the field of factory automation, we may take a hybrid simulation into consideration. The modeling of a hybrid simulation consists of real physical entities, virtual simulation, and central clock algorithm, etc. to carry out the whole system operation. In this paper, we sow a way to construct a hybrid simulation software system in manufacturing environments. We bring in the object-oriented methodology in system design and it can contribute in dealing with a wide variety of production types and configurations. Some classes such as project, product, process, order, schedule, stage are defined. These are used and tested by implementing a specific LSI circuit assembly line process.

• Transactions of The Korea Fluid Power Systems Society
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• v.8 no.2
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• pp.23-28
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• 2011

This paper investigates the motion control of a hydraulic motor-load system using the Simple Adaptive Control (SAC) method. The plant transfer function has been modelled mathematically. The open-loop responses have been obtained experimentally in order to identify the design parameters of transfer function. The hydraulic motor-load system has been modelled using the 3D CAD and imbedded in the hydraulic circuit simulation program to verify the overall performance. The experimental results confirm that the SAC method gives a good tracking performance compared to the PID control.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.721-724
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• 2002

This study deals with a dynamic behavior analysis of pump control regulator varied the swash plate tilting angle with the positive and negative direction. To accomplish it's purpose, modeling and displacement response analysis about principal parts (spool, servo piston, feedback lever, sleeve) of pump control regulator was performed. We have been able to verifying the propriety of servo mechanism and design parameters of pump control regulator by research results. So, it respect to utilized with useful research data at variable displacement control valve development of variable displacement piston pump.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.9
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• pp.795-805
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• 2012

This paper proposes an algorithm and a hardware architecture for a broadcast communication which has the worst bottleneck among multiprocessor using distributed memory architectures. In conventional system, The pipelined broadcast algorithm is an algorithm which takes advantage of maximum bandwidth of communication bus. But unnecessary synchronization process are repeated, because the pipelined broadcast sends the data divided into many parts. In this paper, the MPI unit for pipeline chain algorithm based on circuit switching removing the redundancy of synchronization process was designed, the proposed architecture was evaluated by modeling it with systemC. Consequently, the performance of the proposed architecture was highly improved for broadcast communication up to 3.3 times that of systems using conventional pipelined broadcast algorithm, it can almost take advantage of the maximum bandwidth of transmission bus. Then, it was implemented with VerilogHDL, synthesized with TSMC 0.18um library and implemented into a chip. The area of synthesis results occupied 4,700 gates(2 input NAND gate) and utilization of total area is 2.4%. The proposed architecture achieves improvement in total performance of MPSoC occupying relatively small area.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.251-255
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• 2001

This paper presents a new zero current switching (ZCS) inverter for grid-connected photovoltaic system. The proposed circuit provides zero current switching condition for all the switches, which reduces switching losses significantly. It is controlled to extract maximum power from the solar array and to provide sinusoidal current into the mains. Analysis, small signal modeling and design procedure are presented. The validity of the proposed system is verified by experimental results from the 1.2kW prototype inverter operating at 40kHz.